1. Field of the Invention
The present invention relates to an ink jet head manufacturing method and an ink jet head, the ink jet head having a nozzle plate which has a film having at least one of a water repellent function and an oil repellent function provided on a surface thereof. In addition, the present invention relates to an ink applying apparatus and an ink applying method for applying an organic electro luminescence positive hole transport solution and an organic electro luminescence solution by using this ink jet head. Further, the present invention relates to an organic electro luminescence display apparatus with its high luminescence and long service life using this ink applying apparatus and a method of manufacturing the same.
2. Description of the Related Art
A nozzle plate provided on an ink jet head to be used for an ink jet printer is formed of a material such as a metal, a stainless steel, a ceramics, or an organic film. A number of nozzle holes of several microns to 100 microns in diameter are regularly formed on this nozzle plate.
The above nozzle plate is provided so as to cover an ink chamber of the ink jet head, and the above ink chamber is pressurized due to deformation of an piezoelectric element or the like, for example, whereby the liquid in the ink chamber is ejected in a predetermined direction from the nozzle hole formed on the above nozzle plate.
If the liquid ejected from the ink chamber is adhered or remains at the periphery of the nozzle hole of the above nozzle plate, a liquid to be ejected next interferes with the liquid that remains at the above nozzle plate. Thus, its ejection direction or ejection quantity may change.
Because of this, a film (hereinafter, referred to as a xe2x80x9cwater repellent filmxe2x80x9d) having a water repellent function or an oil repellent function, which is formed of a fluorine based resin such as a fluorine based polymeric film or a fluorine silicone film is provided on one plate face of a side on which the liquid of the above nozzle plate is ejected, whereby the liquid ejected from the nozzle hole is prevented from being adhered or remaining at the periphery of the nozzle hole.
A method of providing a water repellent and oil repellent film on a plate face of a nozzle plate can be roughly divided into a wet coating method such as a dip method, a spray method, or a transcription method (an offset printing method); and a dry coating method using a plasma CVD (chemical vapor deposition) method.
On the other hand, attention is paid to an organic electro luminescence element (hereinafter, referred to as an xe2x80x9corganic ELxe2x80x9d) using a multi-layered film of an organic material (for example, Jpn. Pat. Appln. KOKAI Publication Nos. 63-264692, 63-295695, 1-243393, and 1-245087). There are two methods; a method of producing an organic EL element by vacuum evaporating a low molecule and a method of producing an organic EL element by applying a polymeric solution. In the method of applying a polymeric solution, an area can be easily increased. In particular, this method is suitable for a full color display with its high definition and large screen using an ink jet process.
A water repellent and oil repellent film is provided on a plate face of the above described nozzle plate by using either of these two methods. In any case, any of the following problems has occurred. First, on the nozzle plate, the water repellent and oil repellent film invades into the nozzle hole, and is adhered on its inner periphery face. Thus, the nozzle hole is clogged or the hole diameter is reduced, whereby the quantities of liquids ejected from a plurality of nozzles are not uniform, resulting in degradation of the liquid ejection performance.
In order to remove the water repellent and oil repellent film adhered or remaining on the inner periphery face of the nozzle hole, the respective holes have been drilled. However, a large amount of work is required to remove the water repellent and oil repellent film by using such a method, which is impractical.
Second, if a nozzle plate is made of an metal oxide such as a metal, a stainless steel and a ceramics, even if a fluorine based resin is provided on this plate, the quality of the plate is inferior in respects of reliability such as intimacy or durability.
In order to overcome this disadvantage, as disclosed in Jpn. Pat. Appln. KOKOKU Publication No. 5-5664, there is provided an ink jet head in which a water repellent and oil repellent film consisting of a fluorine polymer is provided on a hole face of a nozzle (a nozzle plate) made of a glass ceramics via an intermediate layer consisting of a silicon polymer by using a plasma CVD method.
The intermediate layer consisting of a silicon polymer is provided between the water repellent and oil repellent film and a nozzle hole face, thereby making it possible to improve intimacy between the water repellent and oil repellent film and the nozzle hole face to some extent.
However, a structure disclosed in this publication is a double-film structure in which the intermediate layer consisting of the silicon polymer and the water repellent and oil repellent film consisting of the fluorine polymer are sequentially formed to be layered with each other. Therefore, the rigidity of bonding faces of the intermediate layer and the water repellent and oil repellent film is not sufficiently obtained, which has not been sufficient in respect of reliability such as intimacy or durability.
On the other hand, when a polymeric solution has been applied by using the ink jet head, the following problem has occurred. That is, an ejection failure may occur while the solution is applied by ink jetting. In the case where such an ejection failure occurs with a display, a display failure may result, and requirements for products are not met. Thus, ejection stability or durability is required for this ink jet head.
It is a first object of the present invention to provide an ink jet head manufacturing method and an ink jet head, the ink jet head having a nozzle plate such that a water repellent and oil repellent coil adhered to an inner periphery face of a nozzle hole can be removed reliably and easily.
It is a second object of the present invention to provide an ink jet head manufacturing method and an ink jet head such that bonding rigidity between a nozzle plate and a water repellent and oil repellent film can be sufficiently improved.
It is a third object of the present invention to provide: an ink applying apparatus and an ink applying method capable of applying an ink with high precision; and an organic EL display apparatus and a method of manufacturing the same in which an ink is applied with high stability and with high precision by using this ink applying apparatus.
In order to solve the above problem and achieve the above objects, the present invention is constituted as follows. A method of manufacturing an ink jet head having a nozzle plate which has a film having at least one of a water repellent function and an oil repellent function formed on one plate face thereof comprises a step of providing the film on one plate face of the nozzle plate; and a step of etching the nozzle plate from the other plate face side, thereby removing the film adhered onto the inner periphery face of the nozzle hole.
An ink jet head manufacturing method for forming a film having one of a water repellent function and an oil repellent function on one plate face of a nozzle plate having a nozzle hole, is characterized by comprising gradually decreasing a first raw material gas containing a metal oxide component and a second raw material gas containing a fluorine based resin component in rate of the first raw material gas from a state in which a rate of the first raw material gas is greater than that of the second raw material gas; and gradually increasing a rate of the raw material gas, thereby forming the film on one plate face of the nozzle plate in accordance with CVD.
The present invention is characterized in that an organic electro luminescence positive hole transport solution and an organic electro luminescence solution are applied by using the above described ink jet head.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.